Senior police officers in the north have warned MPs that a hard post-Brexit border would be an obvious area of attack by dissident republican terrorists.

Giving evidence to the House of Commons Brexit Committee in Co Armagh, the PSNI's Deputy Chief Constable Drew Harris said any infrastructures along the border would give terror groups "a further rallying call to drive their recruitment."

"They have a focus on this. They see it as an opportunity.

"Infrastructure on the border would be an obvious point for dissident groups to rally around and attack," Mr Harris added.

He said the threat from dissident republicans remains severe and that there were four attempts on the lives of police officers over the past year. There were also 58 shooting and over 32 bombing incidents.

Mr Harris told the committee it was regrettable that a lot of the current border conversations "take us back to the 80s."

"We in law enforcement see no rational of that infrastructure at the minute," he insisted.

Mr Harris said that during the 1980s there was a major problem with cross-border burglaries of older people in their homes.

He said many of the culprits escaped justice by heading over the border.

The Deputy Chief Constable outlined a number of shared European initiatives, such as the European Arrest Warrant, shared information systems and joint investigation teams, which have helped in the fight against crimes including human trafficking and drug smuggling.

Mr Harris told the committee he would be concerned if the shared systems were lost.

"The systems are for a safer Europe. It is not a one-way street. We have a lot to offer our European partners after Brexit.

"We are unsure of what the landscape is going to look like going forward. Our responsibility is to do our very best to maintain the safety of everyone on this island.

"That has to be backed up with legislation and policy which allows intelligence and evidence to be shared quickly."

When asked what would happen in the event of a no Brexit deal, Mr Harris said the PSNI would have to fall back on existing legal provisions with the Garda in the Republic.

However, he said a new extradition treaty would be needed in the absence of the European Arrest Warrant.

Assistant Chief Constable Stephen Martin, head of the PSNI's serious and organised crime branch, told committee members there is good cross-border cooperation between the PSNI and the Garda.

He said the two organisations assist each other "across a whole spectrum of crime."

Mr Martin said the PSNI has been sharing intelligence with the Garda in relation to an ongoing drugs feud in Dublin between the rival Hutch and Kinahan gangs that had resulted in a number of murders.